PURPOSE: To accurately perform alignment in spite of the deviation of an original, and to detect a chip or dust which causes trouble in printing without detecting an individual unnecessary dot as an unmatching part and without causing any moire.
CONSTITUTION: In the case of performing plate inspection by comparing the image data of an old plate 1 and a new plate 2 each other, the luminance corresponding to the dots of the original is averaged for the image data by a filter processing part, or the image data is formed by enlarging or reducing either image data and compared with the other image data so as to inspect the matching/unmatching of the image data by an enlarging and reducing inspection part 45, or the differential image data of the image data is obtained and compared with a threshold for sensitivity so as to inspect the unmatching part of the image data by a sensitivity inspection part 46.
KANEDA HIDENORI
TAKASHI SEIKI
ONKAWA TAKEO
ONODA JUN
KUDO HIDEO
HITACHI ELECTRONICS
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